1. Field of the Invention
The present invention relates generally to surgical instruments and, more particularly, to surgical drilling bits and the like and, most particularly, to pseudo-etching of depth indicating bands and/or other identifying markings or indicia on diamond-like carbon coated dental drilling bits and the like used to prepare an osteotomy in the jawbone of a patient.
2. Description of the Related Art
Dental implants are surgically implanted in a patient""s jawbone to provide anchors for prosthetic devices such as artificial teeth, crowns, bridges, dentures and the like. Dental implants allow people who lose their teeth to be able to comfortably smile, speak, and chew.
Typically, the dental implant that is implanted in the bone of a patient""s jaw supports a socket. This socket is accessible through the overlying gum tissue for receiving and supporting one or more dental attachments or components. In turn, these components are useful to support the prosthodontic restoration.
The first step for installing an implant usually involves making an incision in the patient""s gum or gingiva. Next, typically, a hole or osteotomy is formed in the jawbone of the patient. This may involve widening of a pre-existing cavity or the formation of a fresh one. The implant is then fixtured into the osteotomy. More than one osteotomy may be prepared to support a plurality of implants. Once the implant is properly secured in its subgingival position in the osteotomy a healing screw is threaded tightly over the implant.
This is followed by a healing period in which the bone is allowed to grow and surround and retain the implant. This process is called xe2x80x9cosseointegration.xe2x80x9d The gum tissue is also allowed to heal over the implant and the healing screw. For implants in the mandible (lower jaw), healing typically requires about three months; for implants in the maxilla (upper jaw), the healing period is usually about six months.
After the osseointegration occurs and the gum has healed, the gum is reopened by making an incision in it and the healing screw is removed. A suitable healing abutment is attached to the implant. A second healing period ensues in which the gum tissue is allowed to heal around the healing abutment. Typically, this second healing period lasts from four to eight weeks.
After the second healing period, the healing abutment is removed from the implant. Typically, an impression is taken of the patient""s mouth to fabricate a prosthesis or dental restoration. An abutment which supports the final restoration is attached to the implant. Lastly, the restoration is cemented or screwed to the abutment and/or implant to complete the placement of the prosthodontic restoration in the patient""s mouth.
The step of forming an osteotomy typically involves drilling a hole in the patient""s jawbone, utilizing one or more suitable drilling bits. This can be a difficult procedure and can cause discomfort and trauma for the patient, at least partially, due to the pain and shock involved with the penetration of a relatively large drilling bit in a person""s jawbone. Drilling in high bone densities can further exacerbate and complicate the osteotomy preparation.
The high rotational drilling speeds typically involved can also generate a significant amount of heat. This is especially true since the osteotomy is not a through hole. Disadvantageously, the large amounts of heat can cause bone xe2x80x9cnecrosisxe2x80x9d due to burning. Again, this adds to the trauma and suffering of the patient, and can inhibit the desired healing of the bone and osseointegration of the implant.
The high rotational drilling speeds can also result in high frictional forces and torques between the bone and the drilling bit. Undesirably, this increases the risk of bone fracture, and again this is detrimental to the patient. Moreover, the high frictional forces and torques may cause breakage of the drilling bit. Disadvantageously, this further complicates the procedure and adds to the trauma of the patient.
In some cases, dental counterbores are utilized to countersink the osteotomy for receiving a particularly configured implant. Also, dental threadformers may be used to thread the osteotomy for receiving a threaded implant. Both counterbores and threadformers involve removal of bone material and can cause some or all of the above-mentioned disadvantages.
In some instances, an osteotome is used to form an osteotomy in soft bone. An osteotome typically has a cutting tip that is manually manipulated by the dental practitioner to cut/compress the soft bony material. Again, the use of conventional osteotomes can suffer from some or all of the above-mentioned disadvantages.
As indicated above, it can be difficult to perform osteotomy preparing procedures efficiently, and without causing significant discomfort and trauma to the patient. Moreover, the drilling bits, counterbores, threadformers, and osteotome cutting tips are exposed to frictional forces and corrosive environments (in the patient""s mouth and possibly during sterilization). As a result, in many cases, these instruments have to be replaced frequently since wear and corrosion reduce their effectiveness. Disadvantageously, this also adds to the cost of the implant procedure.
It is also important that the bore-holes or osteotomies be prepared to a suitable depth to ensure proper seating of the dental implant. Care should also be taken when an osteotomy is being prepared in parts of the jaw where a nerve or nerve system is located to prevent damage to the nerves. It can be difficult to provide reliable and durable depth indicators during the preparation of an osteotomy.
It is one advantage of the invention to provide a depth gauging system and a method for forming depth indicating bands on amorphous hard carbon coated dental tool bits and the like. The method uses a laser to process, treat or pseudo-etch selected surfaces of the coated tool bit. Advantageously, the laser pseudo-etching creates bands or indicia that substantially preserve or retain some or all of the desirable bulk properties of the hard carbon coating, for example, the corrosion resistance. Desirably, the bands provide visual differentiation during the preparation of an osteotomy in bone material which allows a surgeon to precisely and exactly control the depth of the osteotomy.
In accordance with one embodiment, the invention provides a method of treating the surface of a surgical instrument to provide visual differentiation. The method comprises the step of providing the instrument comprising a cutting head and a mounting shank adapted to engage a handpiece or handle. A hard carbon coating is formed on the cutting head of the instrument. One or more selected surfaces of the cutting head are pseudo-etched to provide one or more bands having a predetermined spacing for indicating the depth of an osteotomy.
In accordance with another embodiment, the invention provides a method of processing the surface of a coated dental cutting instrument to provide visual differentiation. The method comprises the step of providing the instrument comprising a cutting head and a mounting shank adapted to engage a handpiece or handle. An amorphous hard carbon film is formed on at least the cutting head of the instrument. A plurality of selected coated surfaces of the cutting head are laser processed to pseudo-etch a plurality of indicia having a predetermined spacing for precisely indicating the depth of an osteotomy formed in a jawbone.
In accordance with one embodiment, the invention provides a surgical instrument for providing visual differentiation. The instrument generally comprises a main body portion, a coating of amorphous hard carbon applied on at least a portion of the main body portion, and one or more indicia formed on the main body portion. The indicia are formed by laser pseudo-etching of selected surfaces of the hard carbon coated main body portion to provide a depth gauging system on the instrument. Advantageously, the surface finish of the indicia substantially preserves the protective coating properties of amorphous hard carbon.
In accordance with another embodiment, the invention provides a dental drilling system for preparing an osteotomy. The system generally comprises a tool bit, a handpiece for holding the tool bit, a coating on the tool bit in the form of diamond-like carbon (DLC) and a plurality of pseudo-etched bands formed on the coating. The tool bit includes a cutting head for removing bone/tissue material to form an osteotomy. The handpiece is adapted to provide rotational motion to the tool bit. The diamond-like carbon (DLC) coating improves the cutting performance of the tool bit. The bands provide visual differentiation and advantageously are corrosion resistant.
For purposes of summarizing the invention certain aspects, advantages and novel features of the invention have been described herein above. Of course, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.